"I am 31 years old and I have never had an opportunity to go to a game in September that was part of a pennant race," said Chris Knoerlein of Rodgers Forge, who bought tickets last week with a group of eight friends and family members. "It is an incredible feeling to still root for the Orioles during the Ravens season. There is an energy in the city that has been missing for a very long time, and I didn't want to miss the opportunity to be a part of this pivotal week."

Fans have also begun to look beyond the final homestand. Tickets for potential home games in the wild-card playoff and American League Division series go on sale to the public on Orioles.com at 10 a.m. Saturday. The Orioles previously opened postseason sales to season-ticket holders, to those who put $250-per-seat deposits on 2013 season plans and to about 30,000 fans who registered earlier this week for a Friday pre-sale.

Bobby Weaver of Bel Air bought playoff tickets as part of the Friday pre-sale. "This is money that I'm going to have to pinch from other parts of my budget," he said. "But I am 42 years old and I have not been to a postseason Orioles game since I was 9."

The Orioles are expecting crowds in the mid- to upper-20,000s for their series against the Blue Jays Monday through Wednesday (Monday is a single-admission doubleheader). Next Saturday's game against the Red Sox, which will feature the unveiling of Brooks Robinson's sculpture at Camden Yards, is already sold out. The Orioles expect more than 35,000 fans for the Friday night and Sunday afternoon games against the Red Sox.

Such numbers would be similar to those from the last homestand against the New York Yankees and Tampa Bay Rays and far better than what the Orioles drew in recent Septembers. But the crowds would still fall well short of the club's attendance heyday in Camden Yards.

Orioles spokesman Greg Bader said the club is pleased with the sales, noting that fans have bought more than 30,000 tickets for the Toronto series in the last 10 days.

That late rush speaks both to the excitement this team has created and to the behavioral change required for the Orioles to draw large late-season crowds.

"Nobody could have foreseen that this series was going to be as important as it is," Bader said of the three-day set against Toronto. "So we're thrilled to see the outpouring of support, from the individual fan level to the government to businesses. We see the buildings around town turning orange."

The Orioles also discounted certain tickets for the Toronto series, extending a "throwback" pricing promotion that was also in place for the Tampa Bay games during the last homestand. Under that promotion, Eutaw Street bleacher seats were discounted to $4 (they usually cost $19) and left-field lower box seats were discounted from $32 to $8.

Fan after fan said they had purchased tickets on short notice, because they had to be part of a special season. Tom Keller of Biltmore Lake, N.C., will drive up to attend all three Red Sox games, the first two with his sister, who lives in Bel Air. The family grew up three blocks from Memorial Stadium.

"I felt compelled to be there to thank them in person for an unbelievably breathtaking year," Keller said.

For a little context, a mid-week, mid-September series against Tampa Bay in 2011 drew an average of 13,285. A similar series against Toronto in 2010 drew an average of 13,374. So the Orioles are approximately doubling crowds for equivalent series in 2012.

Using conservative estimates for the remaining games, the Orioles project to average about 34,000 fans per game for 13 dates in September, compared to 21,960 for 11 dates in 2011 and 24,664 for 14 dates in 2010.

Through Thursday, the Orioles ranked 22nd in baseball in home attendance with an average crowd of 25,937. That's a noticeable improvement from the 21,943 average of 2011, when they ranked 26th (though attendance leaguewide is up about 800 fans per game). Again using conservative estimates, they project to finish the season with their highest average attendance since 2007.

At lunch hour Friday, a steady trickle of people approached the ticket windows outside Camden Yards to secure seats for next week.

"I have to be there to see if they can make it happen," said Andrew Keir of Mt. Vernon, who bought tickets for Monday's doubleheader against the Blue Jays. "I've been waiting for this for 15 years. It's the first time I've ever been able to care about the Orioles and Ravens at the same time."

Keir attends games every year. "But if they were down in the dumps, getting beaten up in the AL East, I probably wouldn't be going on Monday," he said.

Many patrons wore Ravens purple as they bought their orange and black tickets. Andy and Sarah Schaufele of Locust Point split the difference, he wearing his Haloti Ngata jersey and she a black Orioles T-shirt as they bought tickets for a Wednesday date night at the park.

"It's not often," said Andy Schaufele, "that we have reason to rock both of these at the same time."